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Biomedical subjects

L Bower

Publications and source records attributed to L Bower.

12 recordsLinked to original sources
PubMed2004

Hypertriglyceridaemia in Alström's syndrome: causes and associations in 37 cases.

OBJECTIVE: To document frequency of severe hypertriglyceridaemia in Alström's syndrome (AS) and its relationship to hepatic and renal function, glycaemia and insulin resistance. PATIENTS AND METHODS: Thirty-seven subjects with AS aged 5-35 years, 51% male, were assessed at multidisciplinary clinics in Canada, UK and Italy. Diagnostic criteria were: severe cone/rod dystrophy leading to severe visual impairment in early childhood, sensorineural deafness, moderate overall obesity and normal intelligence. Three patients were treated with thyroxine for primary hypothyroidism and one female patient for secondary amenorrhoea with 20 micro g ethinyloestradial combined oral contraceptive. Two male patients were receiving monthly intramuscular testosterone enanthate for secondary hypogonadism. Fasting bloods were taken for serum insulin, serum glucose, serum triglycerides, hepatic and renal function and glycosylated Hb. Triglyceride levels > 8 mmol/l and fasting serum insulin levels > 16 microunits/ml were considered to represent severe hypertriglyceridaemia and severe insulin resistance, respectively. All subjects with (23) hypertriglyceridaemia also had high insulin resistance, as measured by HOMA modelling. However, there was no significant correlation between log tyriglyceride and log serum insulin or HOMA in the whole group (P = 0.2 and 0.14, respectively). There was no clear relationship between serum triglyceride levels and age, body mass index (BMI), hepatic or renal impairment or glycaemia. CONCLUSION: The first overview of serum triglyceride levels in a significant number of reported cases of Alström Syndrome shows an overlap between severe hypertriglyceridaemia and severe hyperinsulinism, but not a direct correlation between the two nor with insulin resistance measured by HOMA. Triglyceride levels were not related to glycaemia, hepatic or renal dysfunction.

Adolescent↗
PubMed2002

Five year results of a prospective very low calorie diet or conventional weight loss programme in type 2 diabetes.

AIMS: To complete 5-year follow-up of an intensive weight loss programme in established type 2 diabetic subjects. METHODS: Forty-five obese type 2 diabetic subjects, Body mass index (BMI) > 30, expressed interest in an intensive weight loss programme. Group 1 comprised 15 who selected very low calorie diet (VLCD), Group 2, 15 selected intensive conventional diet and exercise (ICD), 15 failed to follow either programme. Group sessions of eight to 15 subjects continued weekly for 6 months, then monthly for 12 months with prospective recording at 3, 6 and 12 months and then annually of quality of life, BMI, waist/hip ratio, blood pressure, fasting blood glucose, serum fructosamine and serum lipids. RESULTS: Weight loss was slower in the intensive conventional diet group than in the VLCD group, but better maintained at 5 years: group 1, 4.8 +/- 6 kg; group 2, 8.9 +/- 4 kg. In the intensive conventional diet group, 5 year high-density lipoprotein cholesterol was increased 1.78 +/- 0.26 mmol L-1 vs. 1.10 +/- 0.32 mmol L-1 at baseline, and diastolic blood pressure reduced 74.5 +/- 13.3 vs. 85.5 +/- 13.3 at baseline, both P < 0.05. CONCLUSIONS: Out-patient VLCD treatment proved safe and effective in overweight diabetic subjects but those who chose conventional diet and exercise had a slower but more sustained weight loss. Diabetic patients willing to attempt VLCD may safely lose sufficient weight to allow major surgery, but weight regain is inevitable. Patients willing to undertake a long-term group programme of conventional diet can sustain significant weight loss for 5 years, but still require antidiabetic medication.

Adult↗
PubMed2000

The importance of p53-independent apoptosis in the intestinal toxicity induced by raltitrexed (ZD1694, Tomudex): genetic differences between BALB/c and DBA/2 mice.

The thymidylate synthase inhibitor raltitrexed (ZD1694, Tomudex) induces greater intestinal toxicity, manifested as diarrhea and weight loss, in BALB/c than in DBA/2 mice. No convincing pharmacokinetic or pharmacodynamic reason for this strain difference has been established. We have investigated whether this strain difference in response to raltitrexed is related to differential susceptibilities of intestinal mucosae to undergo apoptosis and also whether p53 expression, a critical factor in 5-fluorouracil-induced intestinal apoptosis and toxicity, modulates this response. Ten mg/kg or 100 mg/kg raltitrexed were administered as single or double i.p. injections 24 h apart to BALB/c, DBA/2, and p53-/- mice. Apoptosis, mitosis, and tissue damage were assessed in intestinal epithelium, and animal weight was recorded. BALB/c mice developed diarrhea and weight loss following 100 mg/kg x2 raltitrexed, whereas DBA/2 mice did not. BALB/c mice were more sensitive than DBA/2 to induction of small-intestinal and colonic apoptosis 24 h following 100 mg/kg raltitrexed. Inhibition of mitosis was equivalent in both strains. Both strains showed histopathological damage to the small intestine after 100 mg/kg x2 raltitrexed, but only BALB/c mice demonstrated colonic damage. p53-null mice showed the same level of small intestinal apoptosis as their wild-type counterparts 24 h after 100 mg/kg x1 raltitrexed and also the same levels of intestinal toxicity 3, 5, and 7 days after 100 mg/kg x2 raltitrexed. Thus, BALB/c mice were more susceptible to induction of intestinal apoptosis by raltitrexed than DBA/2 mice and also demonstrated more histopathological damage in the colon correlating with the induction of diarrhea and weight loss. In contrast to 5-fluorouracil, the intestinal apoptosis and toxicity induced by raltitrexed were p53-independent.

Animals↗
PubMed1999

Three-dimensional measurement of cerebral microvascular plasma perfusion, glial fibrillary acidic protein and microtubule associated protein-2 immunoreactivity after embolic stroke in rats: a double fluorescent labeled laser-scanning confocal microscopic study.

Early astroglial response to post-ischemic microvascular hypoperfusion may contribute to progressive cerebral microcirculatory impairment and ischemic neuronal injury. Using laser-scanning confocal microscopy and three fluorescent probes, we measured in three-dimensions cerebral microvascular plasma perfusion, astrocytic reactivity, and neuronal injury assessed by fluorescein isothiocyanate (FITC)-dextran, GFAP immunoreactivity, and microtubule associated protein-2 (MAP2) immunoreactivity, respectively, in rats subjected to 2 h of middle cerebral artery occlusion. Three-dimensional quantitative analysis revealed that 2 h of embolic ischemia resulted in a significant (P<0.05) reduction of cerebral microvascular plasma perfusion in the ipsilateral cortex and subcortex. Tissue within the ipsilateral cortex and subcortex with low plasma perfusion exhibited a significant (P<0.05) increase in GFAP immunoreactivity compared with the homologous contralateral tissue. Three-dimensional re-constructed images showed that prominent GFAP immunoreactive astrocytes surrounded large vessels with decreased plasma perfusion in downstream capillaries in the ipsilateral MCA territory when compared to the vessels in the contralateral homologous tissue. Triple fluorescence probe-stained sections showed that tissue with decreased plasma perfusion and with increased GFAP immunoreactivity was accompanied by a reduction of MAP2 immunoreactivity. The present study demonstrates that an impairment of microvascular perfusion induces an early increase in GFAP immunoreactivity, and reactive astrocytes may contribute to a further reduction of cerebral microvascular plasma perfusion. The three-dimensional quantitative imaging analysis used in the present study provides a means to investigate parenchymal cellular responses to changes of cerebral microvascular plasma perfusion after MCA occlusion.

Animals↗
PubMed1998

An intensive weight loss programme in established type 2 diabetes and controls: effects on weight and atherosclerosis risk factors at 1 year.

The efficacy, safety, and effect on cardiovascular risk factors of two intensive weight loss programmes in overweight Type 2 diabetic subjects were studied. The patients were recruited from hospital diabetic clinics and control obese subjects from the community. Obese (BMI >30) patients with Type 2 diabetes mellitus and controls were offered intensive conventional diabetic advice or a very low calorie diet. Weekly 2 h sessions were conducted in two day-room areas of adjacent medical wards of Torbay Hospital. Non-diabetic and diabetic very low calorie diet groups reduced BMI by 6 and 5 kg m(-2), respectively, at 1 year. Waist-hip ratios (-0.06 and -0.05) were also reduced (p = 0.04 and p = 0.01), while HDL/total cholesterol ratios increased (+0.04 and +0.06, p = <0.01). Transient changes in blood pressure and antioxidant vitamin status occurred in the intensive conventional diet group. Fourteen of diabetic very low calorie diet subjects discontinued insulin and oral hypoglycaemic agents for the whole year, and psychological well-being transiently improved. Substantial weight loss and improvement in cardiovascular risk factors could be maintained for 1 year in Type 2 diabetic patients by the use of a very low calorie diet.

Adult↗
PubMed1995

Resection of a massive sacrococcygeal teratoma using hypothermic hypoperfusion: a novel use of extracorporeal membrane oxygenation.

A 33-week-gestation infant with a massive sacrococcygeal teratoma weighted 4,000 g, but the actual weight of the infant was approximately 1,500 g. With the potential for massive blood loss and impaired lung compliance during resection, some type of cardiopulmonary support was necessary. Resection was undertaken with the assistance of venoarterial extracorporeal membrane oxygenation (ECMO) and hypothermic hypoperfusion. Immediately after removal of the tumor, which weighted 2,420 g, the infant was decannulated from ECMO, and the carotid artery was primarily reconstructed end-to-end. The amount of intraoperative blood loss was 550 mL Postoperatively, the child weighted 1,580 g. Follow-up head ultrasound results were normal, and the patient has done well. This is the first reported case in which ECMO with hypothermic hypoperfusion was used for resection of a massive tumor. This experience shows that ECMO is both useful and safe as a means of temporary cardiopulmonary support for resection of massive tumors in infants.

Coccyx↗
PubMed1992

Human serum and urine glycosaminoglycans in health and in patients with chronic renal failure.

Quantitation of uronic acid precipitable by cetylpyridinium chloride (CPC) and electrophoretic separation of glycosaminoglycans were performed on sera from patients with chronic renal failure and compared to normal controls. Serum CPC-precipitable uronic acid (CpUA) levels in patients with renal failure were significantly higher (mean 13.7 mg/L, range 7.1-23.6 mg/L) than normal controls (mean 9.6 mg/L, range 5.1-13.9 mg/L) due to increased concentrations of low sulphated chondroitin sulphate. A positive correlation between serum CpUA and creatinine was found in renal failure patients. Urine CpUA excretion was raised in renal failure patients compared to normal controls with an increased excretion of chondroitin sulphate (Ch-S) of reduced electrophoretic mobility. Heparan sulphate (HS), a major glycosaminoglycan in normal urine, was absent from the urine of these patients. The possible origin of urine glycosaminoglycans and the role of the kidney in glycosaminoglycan metabolism are discussed.

Adolescent↗
PubMed1988

The isolation and characterization of glycosaminoglycans in normal human serum.

The optimization of conditions for the isolation and characterization of human serum glycosaminoglycans (GAG) is described, together with studies of the accuracy and reproducibility of the method. The principle of the method is proteolytic digestion of serum using papain followed by precipitation of GAGs from the digested sample with cetyl pyridinium chloride (CPC). The uronic acid level and electrophoretic separations can be obtained from a 5 ml serum sample. The mean CPC-precipitable uronic acid level in pooled normal serum was 10.8 mg l(-1) serum. Using enzymatic and chemical analysis the major serum GAG was shown to be chondroitin sulphate (CS). Two distinct electrophoretic fractions were identified both consisting of CS but differing in their degree of sulphation. Dermatan sulphate, heparan sulphate and hyaluronic acid were not detected.

Journal Article↗
PubMed1981

Urinary excretion of glycosaminoglycans and hydroxyproline in Paget's disease of bone, compared with neoplastic invasion of bone.

Urinary glycosaminoglycan and hydroxyproline excretion was studied in 11 patients with clear evidence of Paget's disease of bone. Urinary hydroxyproline, cetyl pyridinium chloride (CPC)-precipitable uronic acid and CPC-precipitable hexosamine were expressed as ratios to urinary creatinine. Urine samples were concentrated x 1000 by vacuum dialysis and the glycosaminoglycans examined by electrophoresis on cellulose acetate followed by staining with alcian blue. All the cases studied showed markedly raised hydroxyproline excretion, whereas the uronic acid excretion was normal or only slightly raised in 10 of the 11 cases studied. One patient who had a raised uronic acid and raised hydroxyproline concentration was shown to have osteosarcoma as a complication of Paget's disease. THE VERY HIGH HYDROXYPROLINE: creatinine ratio in all cases of Paget's disease (mean 241.8 mmol hydroxyproline/mol creatinine) contrasted sharply with the cases of disseminated neoplasm, where the ratio was either normal or slightly raised (mean 29.3 mmol hydroxyproline/mol creatinine). The ratio of hydroxyproline to CPC-precipitable uronic acid was also markedly raised in cases of Paget's disease (mean 77.3 mmol hydroxyproline/mmol uronic acid) and was lower in the neoplastic group (mean 14.1 mmol hydroxyproline/mmol uronic acid) but showed no advantage over the hydroxyproline: creatinine ratio in differentiating the two groups. THE URINARY HYDROXYPROLINE: creatinine ratio promises to be of value in differentiating between Paget's disease of bone and neoplastic invasion of bone. A marked rise in CPC-precipitable uronic acid excretion alone is more suggestive of neoplastic invasion of bone, and if associated with a marked increase in hydroxyproline excretion, it raises the possibility of neoplastic change in Paget's disease of bone. The results of this study also suggest that bone collagen, rather than bone tissue in general, is primarily affected in Paget's disease.

Aged↗
PubMed1978

Urinary excretion of glycosaminoglycans in disseminated neoplasm.

Urinary glycosaminoglycan excretion was studied in 24 cases of disseminated neoplasm, 12 of which had unequivocal evidence of skeletal involvement. Urinary hydroxyproline, cetylpyridinium chloride (CPC)-precipitable uronic acid, and CPC-precipitable hexosamine were expressed as a ratio to urinary creatinine. Glycosaminoglycans contained in urine concentrated x 1000 by vacuum-dialysis were separated by electrophoresis on cellulose acetate and stained with alcian blue. Of the 12 cases with clear evidence of skeletal involvement, eight (66%) showed elevation of serum alkaline phosphatase, five (42%) showed elevation of urinary hydroxyproline, and three (25%) showed elevation of urinary uronic acid. It is concluded that urinary uronic acid is not a sensitive index of skeletal involvement in disseminated neoplasm. The most striking feature of the study was the identification of a well-defined fraction indist inguishable from hyaluronic acid in seven (58%) of the cases with evidence of skeletal involvement. Hyaluronic acid is not normally identifiable in adult human urine. The hyaluronic acid excretors showed more consistent biochemical evidence of bone disease (elevation of serum alkaline phosphatase and urinary hydroxyproline) than the non-excretors. The possibility that the urinary hyaluronic acid is derived from degradation of skeletal hyaluronic acid is discussed. An alternative explanation is that the hyaluronic acid is derived from neoplastic cells as part of a reversion of glycosaminoglycan synthesis to a more ;fetal' state, a glycosaminoglycan counterpart of the production of oncofetal antigens by neoplastic cells.

Adult↗
PubMedDate not supplied

The use of hyaluronic acid for sperm selection--evaluation of sperm head ultrastructure.

The percentage of normal spermatozoal plasma membranes and acrosomes was evaluated by electron microscopy before and after a two-step semen washing and swim-up into culture medium containing either bovine serum albumin or hyaluronic acid. Both techniques of sperm selection increased the concentration of motile spermatozoa when compared with the fresh ejaculate (P less than .001). The percentage of sperm with ultrastructurally intact plasma membranes and acrosomes was increased after both separation procedures in comparison with the original ejaculate (P less than .01). In addition, both techniques of sperm selection significantly reduced the content of sample debris, granulocytes, and nonviable spermatozoa (P less than .01).

Acrosome↗